Introduction: Two views of marriage ; Why this book now ; What we will show ; What our argument is not -- 1. Challenges to revisionists : The state has an interest in regulating some relationships? ; Only if they are sexual? ; Only if they are monogamous? -- 2. Comprehensive union : Comprehensive unifying acts: mind and body ; Comprehensive unifying goods: procreation and domestic life ; Comprehensive commitment: a rational basis for norms of permanence and exclusivity -- 3. The state and marriage : Why civil marriage? ; Is marriage endlessly malleable? -- 4. What's the harm? : Weakening marriage: making it harder to realize ; Weakening marriage and expanding government: eroding marital norms ; Making mother or father superfluous ; Threatening moral and religious freedom ; Undermining friendship ; The "conservative" objection -- 5. Justice and equality : The case of infertility ; The injustice of bans on interracial marriage -- 6. A cruel bargain? : Practical needs ; Dignitary harm ; Personal fulfillment, public recognition -- 7. Conclusion -- Appendix: further reflections on bodily union.